An amplifier device has been known which receives a content signal from a content reproduction apparatus (for example, a Blu-ray disc (registered trademark) player) and amplifies a sound signal included in the content signal such that a sound is output from a speaker set.
The amplifier device outputs a video signal included in the input content signal to an external equipment (for example, a television) such that the television reproduces the video signal.
The amplifier device requires a large amount of power consumption (for example, tens to hundreds of watts) in order to amplify the sound signal. The amplifier device has a standby through mode in order to enable only the television to reproduce the video and sound signals, without amplifying the sound signal (see Patent Literature 1).